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Specimen Collection Manual and Test Catalog

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MODIFIED HAM

Geisinger Epic Procedure Code:  LAB5207    Geisinger Epic ID:  198559
Test Restriction:  Orderable by Hematology/Oncology and Laboratory staff only

SPECIMEN COLLECTION
Specimen type: 

Serum AND EDTA Plasma


Preferred collection container: 
Alternate collection container: 
6 mL red-top (plain, non-serum separator) tube
Universal Transport Medium (UTM)/flocked swab
Specimen required: 

Two 1mL aliquots of serum AND 1mL aliquot of EDTA plasma.


Special notes: 

Must have both serum and plasma.



SPECIMEN PROCESSING
Processing instructions: 

Samples need to be centrifuged and aliquoted within 1 hour of collection. Store frozen (-80 preferred).


Transport temperature: 

Frozen (Transport under dry ice).


Specimen stability: 

Room Temperature: Unacceptable. Refrigerated: Unacceptable. Frozen (-20): 72 hours. Frozen (-80): 6 months.


Rejection criteria: 

Thawed in transit, refrozen or clotted sample.



TEST DETAILS
Additional information: 

The mHam assay has a specificity of 85-93%. Patients treated with complement inhibitors will likely produce a negative result. Complement depletion or deficiency (e.g., low C4) in the sample may also produce false negatives. Incorrect or delayed sample processing or transport can be a major cause of complement depletion. Some conditions (e.g., pregnancy) known to increase complement may cause a positive result in the assay.


CPT code(s):  86161, 86160
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Methodology: 
Cell-based Assay
Synonyms: 

mHam 2.0-Complement-Dependent Cell Killing Assay, Brodsky Assay, functional complement activation assay, complement drug inhibition assay


Clinical significance: 

The bioluminescent modified Ham (mHam) cell-based functional complement assay measures complement-driven cell killing, using cell viability as the readout. Positive mHam results reflex to addition of C5 inhibitor to assess whether complement-mediated cell killing is blocked in vitro. Soluble C5b-9 levels are measured as part of this assay. This assay may help to diagnose and treat complement-mediated diseases. The '2.0' in the test name represents recent improvements in this assay (Cole, M. et al. Blood. 2024) from when the assay was first introduced (Gavriilaki E, et al. Blood. 2015).


Doctoral Director(s): 
Randin Nelson MD
Review Date:  08/11/2026

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